Attachment fitting



June 11, 1946. ,1 N GLADDEN-E|AL 2,401,824

ATTACHMENT FITTING Filed Dec. 26, 1942 Y HA QR/5, K/ECH, Fos rf@ HA RR/s b d? fag FOI? THE FIRM A TToR/v/:ms1

Patented June 1l, 1946 ATTACHMENT FITTING John N. Gladden and Leon Zielinski,

Glendale, Calif.

Application December 26, 1942, Serial No. 470,288

Our invention relates to fastening devices, with special reference to fittings for connection to sheets 0r plates, For the purpose of the present disclosure we elect to describe the invention as embodied in a ttingfor releasably connecting inspection plates and other objects to the skin of an airplane. It will be obvious that the invention may have other embodiments for other purposes.

Since the sheet material comprising the skin of an airplane is relatively thin and since an object, such as an inspection plate, must be detachable, it is common practice to mountr on the skin sheet suitable flttings having threads engageable by screws or other attachment means. The imanufacture of such fittings commonly involves severalI machinevoperations and in the aggregate consumes considerable metal.

It .is desirable, especially so in Wartime, to reduce both the manufacturing. cost of the fittings and theamount of metal required. One object of our invention is to providev an attachment fittingpof this type that may be manufactured inexpensively with minimum operations requiring` machine tools. Another object is to provide a tting construction that lends itself readily to the substitution of non-metallic material for metal in a substantial portion of the fitting, and is light in weight.

An attachment fitting of the present type has a base surface for contact with the skin sheet of the airplane. Since the fitting is usually made of relatively rigid material and since the skin sheet of the airplane is relatively flexible, the skin sheet tends to conform to the surface configuration of the fitting base. Since the base Vsurface is flat, and more often than not the skin sheet of an airplane hasl a normal curved configuration, mounting of the fitting usually causes undesirable local distortion and undesirable local stress in the skin sheet. A further object of our invention is to provide a flexible or deformable fitting so that the base surface of the tting may be readily formed to the normal configuration of the skin sheet, thereby to avoid unnecessary local stress in the skin sheet.

Since the skin of an airplane is subject to vibration, it is desirable to incorporate in such a fitting construction some expedient to resist loosening of the associatedscrew means. It is a further object of our invention, therefore, to provide such an vexpedient in a` simple and inexpensive manner.

Our invention'is characterized by the concept of using separate materials for the base portion 19 Claims. (Cl. 85-32) and the screw-engaging portion of the attachment fitting whereby materials best suited for the respective functions of the two portions may be used. A number of objectsof our invention screw-engaging portion and non-metallic material of different properties for the base portion; to provide a construction in which the screwengaging portion is mounted in the material of the base portion, the latter being a base member and the former being an insert embedded in the base member; to provide for embedding such an insert in a manner t0 prevent either relative rotation or 'relative axial movement of the insert; to provide a construction in which the screw loads are transmitted directly to the insert with little or no stress imposed on the base member;- to provide such a dual-part construction in which the base member is made of pliable or deformable non-metallic material to readily conform to any particular skin sheet, even a skin sheet curved in more than one direction; to provide such a construction in which the materialv ofthe base member coacts with the screw means'to resist ll'oosenin of 'the screw means; land to provide such a construction in `vwhich the deformability of the base material is such as to serve a dual purpose, first, in permitting the base member to be flexed to the particular local curvature of a skin sheet, and, second,r in permitting displacement or penetrationlof, the material of the base member by threaded means, thereby to provide vsuch intimate contact with the threaded means as to resist loosening under vibration. v

The above and further objects and advantages of our invention will be apparent in the following detailed description, taken with the accompanying drawing.

In the drawing, which is to be considered as illustrative only:

Fig,'1 is a plan view of a preferred form of our nttins;

Fig. 2 is a bottom view of thetting;

Fig. 3 is a sectional view of the fitting taken as indicated by the line 3-3 of Fig. 2; and

Fig. 4 is asimilar sectional View of the iitting as employed to attach an object'to a skin sheet. The ttingshown in the ldrawing comprises an insert' I0 embedded in aj base member genlera'lly designated Il which as shown constitutes a housing'for the insert I0, The insert I0 is made material of the base member I I in such manner` as to prevent relative rotation of thebase member. formed with a broken peripheralgsurfaogeorpositive engagement by the surrounding material f of the base member to preventrelative rotation.

Thus, in the present construction the'insertilis serrated to provide numerous longitudinal .arecesses I3 forming numerous longitudinal shoulders l5 f orengagementvvith the surrounding material. I ti s als o desirableto provide means for interlo,ck ing thejinsent I Uand the base member I I in a mannerto prevent relative axial movement of thelinsert. 'Ihusin'thepresent construction the linsert IUhas an annular groove I5 forming two j shoulders I'I for positive engagement withthe surrounding material'of the base rmember to prevent rolativeaxial movement o f the in sert. v'For thesamepurpose the bas e mem ber I.I may have ,a flalgeportion I8 overlapping an end surface 1 of` the insertto prevent axial vmovement of the insert relative tothe basemember in ajdireotion away `from the skin sheet 'when the tting is mounted Aona skin sheet, as shown in-Fss. 3 and 4. It .Willjbe noted that the material ofthe base niernberl'l forms'jtheahmllar flange I3 which engagesthe end of theinsert 'I llin apositive manner to prevent y'such relative axialmovement. The base member II has a'housing portionZD embracing .and embeddingthe'insert Ill and has at j least one laterally extendingfportion integral therewithadaptedfor attachment to a skin sheet. :In the present construction Athere are two such lateral portions in the form of wings .2I, the two wingshavingsuitable bores22 to facilitate mount- `Yfi-neraably the nefprmapriity or ,flexibility of 4thematerial ofthe base member IIis such as'to permit'the wing portions 2I to be curved in whatever manner may be required lto conform with the configuration of vthe skinr sheet. AWe have found that Vsome materials ofsuchproperties, for exam- -pleethyl cellulose and Acellulose acetate, may be depended uponadditionally. to cooperate withV the Vscrew means in a novelgmannerjthe screw -means serving as a toolto form threads in the material of the base'member. In'this regard note that in Fig, Sthe annular 'flange I;8 N ofthe base member Adefinesaplain aperture 23 at'the remote or outlet end of .the threaded "bore 25 of the"ins'ert,'the aperture-being ,of a diameter Ysmallerv'than the maximum diameter of the thread-,26 inthe bore and likewise smaller vin diameter than theoutside V`diameter of-'thethread 27 on the screw-:28 shown in Fig. 4.

Eig. 4 1shows .the fitting .mouht ed ontheinner side ofa skin sheet vof an airplanathe fitting being secured by ,suitable rivets 3 'I that pass through .corresponding attachment holes 32 in vvtheskin .sheet. The threaded .bore 2.5! of the-yin'- sert Ill hasy `anentrance endwvhich registerswith Han;attachment vr'opening' 33 in the .-skin @sheet 30 endasubstaoiiellvcooxalaettaohmentoeoniogf 4. in an inspection plate 36. When the screw 28 is inserted in the insert II! and tightened down to the final position shown in Fig. 4, it is apparent that the screw serves as a tool to out a thread in the cylindrical wall of the aperture 23 l formed by the flange I8 of the base member II. The additional thread formed by the screw in the aperture 23 in the base member II cooperates y'with the thread ofltheinsertfn e115 to resist .axial retractionsof thesrew` 2,'=;fandsthe additional thread in the aperture also makes such .intimate frictional contact with the screw as to resist `rotational retraction of the screw under For this purpose rthe insert I') maybev insert in any suitable manner.

vibration.

fItwill-beynoted in Fig. 4 that the tightening of fthe screw 28 draws the insert I0 into pressural contact with the inner surface of the skin i' sheet'sothat loads imposed on theV screw are transmitted directly to the skin sheet without necessarily being transmitted to or through the materialof the base member II. ItWilL be further notedinfFig. 4 that therskin sheet 301s .curved in the planejde'ned by the axeslof v the tworivets 3l and that the fitting corresponds to this curvature. like'rnanner the fitting will `conform toany lateral curvaturein a perpendicular plane definedby lthe axiso'f the. screw'28.

Such' a fitting may 'be ,manufactured ,at relativelylow cost, since 'the'machining operations are c onnedto fabrication of rtheinsert IIL- the base member II being vsimply moldedaround the Sucha tting'- will alsogivea maximum ofservice for va minimumof weight.Y y .i` Qur disclosurein specific detailof th'epreyferred veIrlliloillflflen11 of' Ollr, invention suggests ,variouschangesand substitutions that may bemade under our basic concept, and we reserve theright erly'liewithinthe scopjeofour appended claims.

We claim asourinventionzl `1. A fitting of the. character .described .forcennecting .threaded members to objects o flyarious Suraceurvatilre.' comprising: 1a 'body .'oftoueh material having; a threadedbore to receive 'one 'of saidthreaded members; .an d.a molded base ,memberhaving a portion .embedding'said body land atleast onelateral portion .forjattachment utol a Vcurved object, said base member'lbejng of deformable plastic material to permit `d"lat eralportion toponform to variousfsurfalcecurvatures, said plastic base having .ian aperture '1ocated for threaded Yengagem ent of one -ofj said threaded members ,therein `vand having a sufficiently smaller diameter than *the outsidedi- 'amet'er ofsaidthreaded memberfforaccomplish- Ament of "said 'threaded Vengagement 'by deformation-'of the plastic Wall of said aperture.A

'2. ?Atting ofthe character describ'edfgorconnecting a threadedmember to 'an vobje ct,co'rr1'1orisfing: a body-of tough-material havingI a threaded vbore provided with an 1 entrancecend receive said'threaded'member; and a base of plastic-matachmentito saidQbjeCt,i said -b'ase i inember overlapping the 'end of lsaivzrbody` rremotefrom said entrance end to .resistaxialimovraent1ct-'the body EEPV@ the .lbe member, a'dl' ,Plastic jeagernentjof sa-id ,threaded ,v having a .sufncienilysmalle outside ,diameter of saidmbradfe rhomb'e .toiaocomplis'h said threaded' engagement by,freien riaT .tion v.of .the .plasti material ;surr 'undng 1-said .aperture.

3. A iitting of the character described for connecting a threaded' member to an object, comprising: a; body oftough material having a threaded bore provided with an entrance end to receive said threaded member; and a base member of plastic material embedding said body and adapted for attachment to said object, said body having a broken peripheral surface to resist rotation of the body relative to the base member, said base member overlapping the end of said body remote from said entrance end to resist axial movement of the body relative to the base member, said plastic base having an aperture locatedfor lthreaded engagement of said threaded member therein and having a sufliciently smaller diameter than the outside diameter of said threaded member to accomplish said threaded .engagement by deformation of the plastic material surrounding said aperture.

. 4. A fitting of the character described for connecting threaded members to objects of various surface curvature, comprising: a body having a threaded'bore to receive said threaded member; and a base member adapted for attachment to said object, said base member embedding said body and providing an aperture'at one end of said bore smaller in diameter than the outside diameter of said threaded member, the material of said base member being deformable whereby said threaded member may form a thread in said apertureand whereby the base member mayy be readily deformed to a surface curvature of said object.

5. A tting according to claim l wherein the threaded bore has an entrance end to receive the threaded member and a remote end through which said threaded member projects, said aperture of said smaller diameter in said base member being at said remote end. 6. A fitting of the character described for en gagement by a threaded member to connect something to the outer side of a Wall having attachment holes, said fitting comprising: a body of tough, substantially non-yielding material hav- `ing a threaded bore to register with one of said attachment holes from the inner side of said wall for engagement by said threaded member; and a base member having at least one lateral portion to underlie another of said attachment holes and having an aperture to register with said other hole for anchorage to said wall, said base member .being of deformable plastic material to permit said lateral portion to conform to varying surface curvatures, and said base member embracing said body, said body having at least one shoulder engaged by said base member to resist axial movement relative to the base member.

7. A fitting of the character described for engagement by a threaded member to connect something to the outer side of a wall having attachment holes, said fitting comprising: a body of tough material having a threaded bore to register with one of said attachment holes from the inner side of said wall for engagement by said threaded member; and a molded base member of plastic having at least one portion to underlie one of said attachment holes for anchorage to said Wall, said base member embedding said body, said body having at least one longitudinally positioned peripheral recess for engagement With said base member to resist rotation relative thereto and having at least one circumferentially positioned recess for engagement with said base member to resist axial movement relative thereto.

8. A tting'of the character described for en- 6 gagement by la threaded member to connect something to the outer side of a Wall having attachment holes, said fitting comprising: a body of tough material to contact the inner side of said.

eral surface for engagement with said base member to resist rotation relative to the base member, said body providing at least one shoulder in engagement With said lbase member to resist axial movement relative to the base member.

9. A fitting of the character described for connecting threaded members to Walls .of various curvature, comprising: a body of tough material having a threaded bore to receive said threaded member; and a base member having a portion embedding said body and at least one Wing portion for attachment to said Wall, said body having a broken peripheral configuration to'resist rotation of the bodyv relative to the base member, said base member being fabricated from deformable plastic material to permit said Wing portion to conform to various Wall curvatures, said plastic base having an aperture located for threaded engagement of said threaded member therein and having a sufciently smaller diameter than the outside diameter 0f said threaded member to accomplish said threaded engagement by deformation of the plastic material surrounding said aperture.

10. A tting of the character described for connecting threaded members to Walls of various curvature, comprising: a body having a threaded bore to receive said threaded member; and a base member having a portion embedding said body and at least one lateral Wing portion for attachment to a Wall, said body having a broken peripheral surface to resist rotation of the body relative to the base member, said body providing at least one shoulder to resist axial movement of the body relative to the base member, said base member having an aperture at one end of said threaded ibore of smaller diameter than the outside diameter of the threads in said threaded members, said base member being fabricated from deformable material to permit said wing portion to conform to various Wall curvatures and to permit a threaded member1 inserted in the fitting to form threads in said aperture.

11. A fitting according to claim l0 wherein the threaded bore of the body has an entrance end to receive said threaded member and an outlet end through which the end of said threaded member projects, said aperture of smaller diameter than the outside thread diameter being positioned at said outlet end.

12. A fitting of the character described for engagement by a threaded member to connect something to the outer side of a curved wall having attachment holes, said fitting comprising: a body of tough material having a threaded bore to register with one of said attachment holes for engagement by said threaded member; and a base member having at least one portion to underlie another of said attachment holes for anchorage to the Wall, said base member embedding said body, said body having at least one shoulder engaged by the base member to resist rotation relative to the base member and at least one shoulder engaged by the base member to resist axial -movement1 relativefto.thebasemember, sadlbase member being of "deformable plastic materiali-to vpermit/said oneportion tolconformtoawah 'cur- .vature I 13. A "tting ofthe 4characterdescribedfor engagement by-a threaded memberto conneotfsome- .thingito the outerside of Iacur'vedwallhaving. at-

tachment holes, said vfitting "comprisin'g: rag/body having a threaded bore v`to rreg'ister .with-one of saidattachment holes fromthe inner sidefofrlsaid `Wall for engagement'by'said threaded member; -anda base member having 'at least .one portion to underlie 'another of fsaid attachment vholes for 4movement of the -body relative :to the 'member away from theinnerl face oflthe wall, said'memvber having an kaperture at 'one `end of said threaded bore. ofA smaller diameter lthan'the 'outer diameter "of the-threads of said threaded member,V said base member being i of deformablelmaterial" whereby the basemember Vmay conform to the lwall curvature and .whereby threads may be formed in saidaperture by said threaded member Ato resist loosening of 'the' threade'drmember.

14.A A tting according to claim 13=wherein the portion of the 'basemem'ber overlapping the end of the threadedbody contains the apertureof smaller diameter lthan"the outer `thread diameter.

15. In combination: lfa body having a vthreaded bore to receive a threaded'member; a housing of deformable material peripherally surrounding saidbodyand having a'ange overlying one-end of Isaid body, `said flange having a, cylindrical- Y walled-aperture at-the corresponding lend ofsaid 'bore and aligned therewith, said aperture being adapted to receive said threaded member v`but having `a suiciently smaller diameter than the outside vdiameter of therthreads of said threaded member for said member lto Cut-athread'in vthe cylindrical wall ofsaidaperture and means lockinglsaid-housingagainst movement relative to said body, said locking means including means-to 1erevent lrelative axial movement of said body and housing.

Y16,-A tting of the characterdescribed and adapted to receive a-threadedmemben comprising: a metallic-body providing a-threaded'bore having an'entrance'fend adapted toreceivelsaid threaded member and van exit end from which said threaded member is adapted to extend; a base-'member providinga housing portion having a cavity yto jreceive said \body,said housing -portionn peripherallysurrounding said-body; said base memberl providing also at leastvone win-g portion extending outwardly from sa-idhousing portion; interengaging means for preventing rotation of sai'd'body in -said cavityof said :housingportion anda ring of vdeformable material :retained-by said'housing portion adj-acentithatfend `orsaid body -f-which is Vat the feXitend' o'f .rsaid fbore, said vring providing an 'aperture-aligned `Withisaid threaded bore land of' such '.diameterastofre'- 'ceiversaidmemben the 'diameter ofsai'diaperture than the` outside diameterfof `the'threads -of `said threaded member 'forsaidfmember vto 'cut athread inf the cylindrical Awalll of said aperture gandfmeans locking ysaid Vhousing against movement frelative tosaidbcdy. Y

1:8. In -combination La *body` having a 'zthreaded bore t0 receive a threaded member; a housinglof deformable material peripherally surrounding saidbody land havinga flange overlying onefend of said body, said ange having .a 'cylindricalwalledaperture atthe corresponding end'of said bore and aligned therewith, isaidapertureibeing adapted to receive said threaded member-ibut having a sufficiently Asmaller diameter than s the outside diameter'v of the threads :offsaid threaded member for said member .to cut-a thread; in., the cylindrical wall ofsaid aperture, saidbody having an exposed `bearing surface at. one end of :said bore, and said housing entirely surroundingzsaid body peripherally and providing an exposedbearing surface whereby-.both of said bearingsurfaces engage an object to which said parts are attached; and 'meansdlocking said housing against -movementf'relative to said body.

.'19. Aitting ofthel characterzdescribed foren- 'gagement by a threaded member-*to connect something to'theouterside of a' wall.:havingfattach ment holes, said ftting comprising: a body --of tough, substantially noneyieldingnmaterial fha-ving f a 'threadedxbore :to register-.With 'one of said attachment holes from the inner side of said :wail for .engagement byv said threaded member; 4andra baser member lfiavingvatfleast one lateral portion to underlief-another'ofv said attachment holes-.and having anaperture to registerwithsa-i'd other hole for -an'choragerto saidiwally. said-base memberbei ing of deformableLplasticimaterial toipermit'said lateral portion =to'=conform.to .varying surface rcurvatures, and-said -base memberl embracinglsaid body, saidl :bodyf having. .atV Aleast `one shoulder-engaged by'saidbase member tc resist rotationsirelativetothe base member. e

. @JOHN '.GLADDEN. Y

fLEON-:ZIELINKSKL 

